Brugada syndrome in patients with acute febrile illness

BackgroundBrugada syndrome (BrS) is an inherited electroclinical syndrome and can be occasionally precipitated by fever. The prevalence of Brugada-type electrocardiographic patterns (BTEP) due to febrile illnesses have not been previously studied in India.Materials and methodsBetween June 2014 and December 2015, 525 consecutive patients admitted to a government hospital with acute febrile illness were retrospectively enrolled. In addition to their investigations for workup of fever, ECGs were analyzed and BTEP types 1 and 2 were noted. Daily ECGs if available were perused to document reversal.ResultsBTEP was seen in 23 (4% 95%CI: 2.9–6.5%): BTEP type 1 (Brugada syndrome) in 11 patients (2%; 95%CI 1.2–3.7%) and BTEP type 2 in 12. All patients with BrS (BTEP type1) were males; mean age and temperature were 37.7 years (SD: 17.6) and 38.8 °C (SD: 0.6), respectively. There were no significant differences in age, temperature or ECG parameters between patients with BTEP and those without. These patients neither had cardiac symptoms nor family history of sudden cardiac deaths. Bacterial infections were the commonest cause of fever in patients with BrS. All BTEP changes resolved with defervesence of fever except in one.ConclusionThe prevalence of the fever induced BrS is higher in our study group and is comparable to estimates in Southeast Asian populations. An ECG should be considered in all febrile patients. Further studies are required for better characterization and risk stratification of these patients.     

II导联RWPT标准鉴别宽QRS波的早搏

目的探讨应用Ⅱ导联R波峰时间（RWPT）法对宽QRS波早搏的鉴别诊断价值。方法对已确诊的192例宽QRS波早搏患者，计算应用Ⅱ导联RwPr法对宽QRS波诊断的准确率。结果192例宽QRS波早搏患者中，已确诊的室性早搏130例，室上性早搏伴室内差异传导62例。应用Ⅱ导联RWPT法再鉴别其激动是室性还是室上性伴室内差异传导，发现真阳性112例、假阳性8例、真阴性54例、假阴性18例；敏感度85．38％，特异度87．00％，阳性预测值93．33％，阴性预测值76．39％，准确度86．46％。结论应用Ⅱ导联RWPT法鉴别宽QRS波早搏有较高的敏感度、特异度。     

ST Segment Elevation in One Lead: A Case Report

Background: We describe an unusual finding in an electrocardiogram showing ST‐segment elevation not related to coronary artery stenosis, pericarditis, bundle branch block, or other well known disorders. Case Presentation: A 60‐year‐old African American woman admitted for elective coronary artery bypass graft surgery. A temporary pacemaker with pacing wires was placed intraoperatively for prevention and treatment of postoperative bradyarrhythmia. One day following uneventful surgery, her electrocardiogram demonstrated marked ST segment elevation confined to lead V₆. These changes were comparable to tracings obtained from direct epicardial electrocardiogram, due to contact between the V₆ electrode and the temporary pacemaker ventricular lead wire. Conclusion: Current‐of‐injury patterns are represented on surface electrocardiogram by deviations of the ST segment from the isoelectric baseline. The pacing wire causes direct localized epicardial current‐of‐injury, affecting the action potential and the resting membrane potentials of cardiomyocytes. Our case report demonstrates epicardial current‐of‐injury pattern obtained via surface rather than epicardial electrocardiogram, with surface leads as surrogates of epicardial tracing. Measurement of ST‐segment shifts from the epicardial electrocardiogram has been shown to provide a more sensitive measurement of ischemia when compared to surface precordial ECG.     

Effet d’un effort intermittent d’intensité variable sur la variation du QT et du risque de mort subite chez des élèves camerounais

IntroductionSeveral cases of sudden deaths are observed among students practicing sport and physical activity (SPA). Just few studies have been carried out on the variation of the QT (interval) and risk of sudden death during sporting exercises.AimTo determine the effect of variable intermittent stress intensity on the variation of QT and the risk of sudden cardiac death.Patients and methodsForm 4, lower sixth and upper sixth students were recruited from a high school in Douala (Cameroon). Each subject was tested; starting with a 2-km walk followed by a sprint race or an endurance race, protocol I (P1) or the reverse; protocol II (P2). Two electrocardiograms were recorded; prior to the beginning of the SPA and 5 minutes after the last race. QT was corrected using four formulas.ResultsForty-one subjects (21 women and 20 men), mean age 18 ± 2 years were recruited. At the end of the exercise, corrected QT increased with Bazzet's formula and decreased with Frahmingam's formula. The difference was not significant with Fridericia and Hodges formulas. The frequency of long QT was higher at the end of the exercise with Bazzet's formula (12.2% vs. 24.4%, P = 0.009) while the difference was not significant for the other formulas.ConclusionThe risk of sudden cardiac death increases significantly after SPA. More studies on large samples are needed.     

Characterization and Management of Arrhythmic Events in Young Patients With Brugada Syndrome

Background

Information on young patients with Brugada syndrome (BrS) and arrhythmic events (AEs) is limited.

Postural Orthostatic Tachycardia Syndrome: JACC Focus Seminar

Postural orthostatic tachycardia syndrome (POTS), the most common form of orthostatic intolerance in young people, affects approximately 500,000 people in the United States alone, typically young women at the peak of their education and the beginning of their working lives. This is a heterogeneous disorder, the pathophysiology and mechanisms of which are not well understood. There are multiple contributing factors and numerous potential mimics. This review details the most current views on the potential causes, comorbid conditions, proposed subtypes, differential diagnoses, evaluations, and treatment of POTS from cardiological and neurological perspectives.     

Piezoelectric Electrocardiographic Artifact in a Patient after Surgery with Bradycardia and Hypotension

A 64‐year‐old man was evaluated by a rapid response team for altered mental status shortly after an uncomplicated surgery. He was found to be hypotensive and bradycardic, and an emergent electrocardiogram showed extra “P” wave complexes, ultimately found to be piezoelectric artifacts from a fluid infusion pump. Equipment‐related artifacts have been known to mimic arrhythmias prompting unnecessary therapeutic interventions including antiarrhythmics and direct current shocks. Timely recognition of the unusual properties of the complexes resulted in the avoidance of atropine, epinephrine, or transcutaneous pacing in a rapid response team scenario.     

The possible antianginal effect of allopurinol in vasopressin-induced ischemic model in rats

The anti-anginal effects of allopurinol were assessed in experimental model rats of angina and their effects were evaluated with amlodipine. In the vasopressin-induced angina model, oral administration of allopurinol in dose of 10 mg/kg revealed remarkably analogous effects in comparison with amlodipine such as dose-dependent suppression of vasopressin-triggered time, duration and severity of ST depression. In addition, allopurinol produced dose dependent suppression of plasma Malondialdehyde (MDA) level, systolic blood pressure, cardiac contractility and cardiac oxygen consumption; while in contrast, amlodipine minimally suppressed the elevation of plasma MDA level. Endothelial NO synthase (eNOS) expression, serum nitrate were strikingly increased, however lipid profile was significantly reduced. Seemingly, allopurinol was found to be more potent than amlodipine – a calcium channel antagonist. To conclude, it was explicitly observed and verified that on the ischemic electrocardiography (ECG) changes in angina pectoris model in rats, allopurinol exerts a significant protective effects, reminiscent of enhancement of vascular oxidative stress, function of endothelial cells, improved coronary blood flow in addition to the potential enhancement in myocardial stress. Moreover, our findings were in conformity with several human studies.